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91.
Kafeel Ahmad Zafar Iqbal Khan Asma Ashfaq Muhammad Ashraf Nudrat Aisha Akram Muhammad Sher Hazoor Ahmad Shad Vincenzo Tufarelli Antonio Lonigro Mariano Fracchiolla Eugenio Cazzato 《Environmental Earth Sciences》2017,76(8):322
Bio-concentration of elements such as Mo, As, Se, Fe, Cu, Zn, Ni and Pb was analyzed in spring onion (Allium fistulosum L.) in three different locations of central Punjab, Pakistan. At location GW, relatively low level of hazardous elements was found in spring onion, suggesting that groundwater is a safe source of water for irrigating food crops. The pH of soil at wastewater irrigation was found less acidic (pH 7.4) than the other sites. The range of concentration in the different samples of spring onion was as follows: 6.15–8.16 mg kg?1 for Mo, 2.77–4.28 mg kg?1 for As, 0.395–0.705 mg kg?1 for Se, 36.73–48.17 mg kg?1 for Fe, 10.58–16.26 mg kg?1 for Cu, 28.87–39.79 mg kg?1 for Zn, 6.66–8.75 mg kg?1 for Ni and 4.33–6.09 mg kg?1 for Pb, respectively. High bio-concentration of Zn (15.37) from soil to spring onion was found at canal water irrigated location. The estimated daily intake of metal for spring onion was less, but the health risk index was higher than 1 for Mo, As, Cu, Pb and Ni, respectively. This was due to higher proportion of spring onion in diet, which consequently increased the health risk index for metals. Therefore, it is recommended to avoid growing vegetables in untreated urban and rural wastewater containing elevated amounts of metals. 相似文献
92.
93.
S. N. Jamal M. Z. Iqbal M. Athar 《International Journal of Environmental Science and Technology》2006,3(4):411-416
A greenhouse experiment was conducted to determine the phytotoxic effect of aluminum and chromium on the germination and early growth of two wheat (Triticum aestivum) varieties Anmol and Kiran. Seed were treated with 40, 80, 120 and 160 ppm of aluminum and chromium solution individually and in combined form. Observations were made on seed germination, root, shoot and seedling length, and dry biomass. Seed germination and dry biomass showed no effect of aluminum, chromium and combined treatment. Root, shoot and seedling length of both the varieties showed significant (P<0.05) decrease as compared to control. The growth was also reduced as the concentration of aluminum and chromium increased. Seedling length decreased in both the varieties at all the concentration of different treatment of aluminum, chromium and combined treatment. Attempts are being made in different laboratories to construct novel plants using genetic manipulation technologies that may have a greater tolerance to the presence of toxic metals. The results of the present study may help in understanding the mechanisms involved and their possible use in pytoremediation. 相似文献
94.
Sh. N. Jamal B.Sc. M.Sc. M. Z. Iqbal B.Sc. M.Sc. Ph.D. M. Athar M.Sc. M.Phil. Ph.D. D.Sc. 《International Journal of Environmental Science and Technology》2006,3(2):173-176
Prosopis seeds were grown under controlled environment in solution of aluminum and chromium at different concentration alone as well as combined together. The effect of these metals was studied on seed germination, root length, shoot length, seedling length and dry biomass. Aluminum and chromium alone, and combined together showed no effects on germination and dry biomass. Chromium alone was found toxic to root, shoot and seedling length. However, application of different concentrations of aluminum increased the root, shoot and seedling growth. It may be concluded that aluminum is not as toxic as chromium, and their combined treatment showed the intermediate effect by ameliorating the impact of one another. 相似文献
95.
Experimental Calibration of ISRM Suggested Fracture Toughness Measurement Techniques in Selected Brittle Rocks 总被引:1,自引:4,他引:1
Summary A wide variety of specimen types and methods are employed in fracture toughness measurement of rocks, which result in scattered
values for the same rock type. In order to provide some consistency to the values, the International Society for Rock Mechanics
(ISRM) recommended three suggested methods using core based specimens, the Chevron Bend (CB) test, the Short Rod (SR) test
and the Cracked Chevron Notch Brazilian Disc (CCNBD) test. This standardization helped obtain more consistent values but still
a variation of 20–30% was observed in the values of fracture toughness obtained with the CB and SR methods. The values obtained
with the CCNBD method were found to be consistently lower (30–50%) than those of the other two methods (CB and SR). Many reasons
have been offered to explain this deviation. These include size of the specimen, anisotropy of rock, a dimensionless parameter
in the fracture toughness calculation equation for the CCNBD test, etc. A comprehensive test program was initiated to identify
the cause of these discrepancies between the CB and CCNBD methods. Three brittle rock types were selected for the study and
more than 200 tests were conducted to measure the values of fracture toughness.
A rigorous statistical analysis was carried out to determine the confidence level and find the significance of the test results.
It was found that the CB and CCNBD methods were very comparable provided the correct equation for fracture toughness calculation
was used for the CCNBD method and the size of the specimens was selected carefully. The error in the ISRM 1995 formula of
fracture toughness for the CCNBD method could be the major factor responsible for the consistently lower values obtained with
the method. 相似文献
96.
This paper describes the geological, geotechnical and chemical properties of some Sabkha (lagoonal) soils in the Benghazi plain. Several buildings constructed on such soils show tilting and cracks. The cause of this trouble has been traced to the special characteristics of Sabkha soils. It is suggested that improved mix design and dense concrete should be used so as to make concrete in the foundation impermeable. 相似文献
97.
98.
Naseer Shah Haq Tanveer Ul Khan Abdullah Tanoli Javed Iqbal Khan Nangyal Ghani Qaiser Faizan-ur-Rehman Shah Syed Tallataf Hussain 《Natural Hazards》2021,106(1):965-989
Natural Hazards - The Landslide happens in mountainous regions due to the catastrophe of slope through intensive rain and seismicity. The Himalayas is one of the susceptible parts of the world in... 相似文献
99.
Natural Hazards - In depth assessment of seismicity distribution for a particular region like Fukushima, prefecture is key towards reliable seismic hazard analysis for the area. Assessment of... 相似文献
100.
Bailongjiang watershed in southern Gansu province, China, is one of the most landslide-prone regions in China, characterized by very high frequency of landslide occurrence. In order to predict the landslide occurrence, a comprehensive map of landslide susceptibility is required which may be significantly helpful in reducing loss of property and human life. In this study, an integrated model of information value method and logistic regression is proposed by using their merits at maximum and overcoming their weaknesses, which may enhance precision and accuracy of landslide susceptibility assessment. A detailed and reliable landslide inventory with 1587 landslides was prepared and randomly divided into two groups, (i) training dataset and (ii) testing dataset. Eight distinct landslide conditioning factors including lithology, slope gradient, aspect, elevation, distance to drainages, distance to faults, distance to roads and vegetation coverage were selected for landslide susceptibility mapping. The produced landslide susceptibility maps were validated by the success rate and prediction rate curves. The validation results show that the success rate and the prediction rate of the integrated model are 81.7 % and 84.6 %, respectively, which indicate that the proposed integrated method is reliable to produce an accurate landslide susceptibility map and the results may be used for landslides management and mitigation. 相似文献